Cleaning of articles



Aug. 2, 1932. A. FOWLER ET AL CLEANING OF ARTICLES Filed Au 26, 1929 E mv M m.

35 traverse Patented Aug. 2, 1932 ALEXANDER rowura AND ENGLANDApplication aiea August 26, 1929,

This invention relates to the cleaning of articles and more especiallyto the cleaning of metallic articles as a preparatory to their coatingwith plate, paint, varnish, lacquer B or the like.

In order to obtain the required finish in plated, painted, lacquered andsimilarly coated articles, it is essential that their surfaces berendered free from any dirt, grease,

scale or other foreign matter prior to the application of the coating,and it is the main object of the present invention to provide a methodand app r atus for ensuring the required cleansing of articles by acomplete removal of any grease, dirt or other foreign matter from theirsurfaces.

A further object is to minimize the losses of washing or solvent mediumemployed, thereby effecting economy, and a still further object is toprovide a continuous cleaning process.

In accordance with the present invention the method of cleaning articlesconsists in conveying the articles firstly through a vapour solventadapted to remove any soluble extraneous matter, their surfaces, andsecondly through a pickling bath adapted to remove any residue oreignmatter such as scale and thus render the surfaces of the articlessuitable for subsequent treatment.

Apparatus for carrying out the invention essentially comprises a vapourbath, a pickling bath and a conveyor arranged to the articles insequence through the said vapour bath and said pickling bath.

In a preferred embodiment of apparatus for carrying out the invention,an endless conveyor is associated with an open vapour bath and apickling. bath containing a. suitable acid solut1on, the articles beingfed to the conveyor and after passage through the respective baths beingdelivered with their 5 surfaces cleaned from any foreign matter,

and ready for subsequent treatment.

Where desired a water wash may be provided for the purpose of removingany traces of acid from the articles after their passage through thepickling bath.

The vapour bath can conveniently consist KENNETH JAMES LAND, ASSIGNOBSTO CARRIER ENGINEERING COMPANY LIMITED,

particularly grease, from RENNIE ROBERTSON, OF LONDON, ENG- CLEANING OFARTICLES Serial No. 388,522, and in Great Britain November 1, 1928.

of a shallow trough containing a suitable vapour solvent, for exampletrichlorethylene, maintained in a vapourous form by any suitable means,for example, by heating pipes disposed in the trough, and thearticleswhich are conveyed through the bath at normal or roomtemperature, i. e. below the condensation temperature of the solventoncontacting with the vapour, efiect its condensation on their surfaces,so that any soluble matter on the surfaces is dissolved in thecondensate and falls to the bottom of the bath in solution. 1

The pickling bath to which the articles are conveyed after their initialtreatment in the vapour bath, may comprise a well containing a suitableacid, say sulphuric, hydrochloric or phosphoric acid, depending on thefinish which is to be applied to the articles, and the conveyor isarranged with regard to the bath so that the articles are dipped in theacid during their progress along the conveyor, whereby removal of anyscale or other matter deleterious to the resultant finish is effected.

If desired, a drying chamber or chambers can also be included in thecircuit of the conveyor sutsequent to the pickling bath and/or betweenthe vapour and pickling baths.

The invention will be further described with reference to theaccompanying sheet of explanatory drawing which illustratesdiagrammatically and by Way of example one embodiment of apparatus forcarrying out the invention, and in which:

Fig. 1 is a longitudinal section of the apparatus illustrating thearrangement of conveyor and associated vapour and pickling baths, and anadditional water wash for removing any traces of acid from the cleanedarticles after their passage through the pickling bath;

Fig. 2 is a section through the vapour bath on the line IIII of Fig. 1also illustrating a. regenerating apparatus for the vapour;

Fig. 3 is a section through the pickling bath on the line IIL-III of Fi1; and

Fig. 4: is an end elevation o the general apparatus shown in Fig. 1.

OF LONDON,

.bath is conveniently maintained Referring now to the drawing, 1represents a conveyor driven by any suitable source of power, forexample an electric motor, and rotating in an anti-clockwise directionon carrier wheels 2 and 3 suitably supported on frames 4 from the bed 5of the apparatus. 6 generally designates a. vapour bath, hereafter morefully described, guide pulleys 7 directing the conveyor 1 through thevapour zone, and 8 generally designates the pickling bath, the conveyorbeing directed into this bath by means of guide pulleys 9.

An additional water wash bath 10 is also indicated in Fig. 1, throughwhich the conveyor is directed-by means of guide pulleys 11.

The vapour bath 6 comprises a hollow trough 12 open at 13 and 14 topermit entry and exit respectively of the conveyor 1-. The trough 12 iskept supplied with a suitable vapour solvent, say trichlorethylene,through inlets 15 disposed in the side of the trough, and the trough ismaintained at a temperature sufficient to maintain the solvent invapourous form by means of heating coils or pipes 16 shown disposed onthe base 17 of the trough 12.

The articles 18 to be cleaned are fed to the conveyor at 19 at atemperature below the condensation temperature of the particular solventin use in the vapour bath 6 so that on their contacting with the vapourin the bath 6 condensation is effected on their surfaces with resultantsolution of any grease, the solution of grease and solvent falling tothe base 17 of the trough 12 where it is drawn off through conduits 20,say to a still 21 as illustrated in Fig. 2. When using trichlorethylenethe articles can be fed to the vapour bath 6 at a normal or room temperature of about 60 F; while the vapour at a temperature of about 190F. 'withthis solvent. A source of heat 22, conveniently a Bunsen burner,steam coils or electric resistance, is shown associated with the still21 in Fig. 2, and serves the purpose of heating the condensed solvent toeffect its regeneration, the regenerated vapour being returned to thebath 6 through the inlets 8 with which the still communicates by meansof a conduit 23. Residue grease removed from the articles 18 by thesolvent is drawn off as required from the base of the still 21, a draincock 24 being provided for that purpose.

Preferably a plurality of stills are associated with the vapour bath soas to permit of continuous operation of the apparatus even during thecleaning of one or other of the stills, and the source of heat 22 canconveniently be regulated by a thermostat 25 disposed in the trough 12of the vapour bath,

6 and subject to temperature fluctuations in the vapour so as to cutdown the regeneration as required. Thermostatic regulation of the.

heating coils 16 may also be provided as illustrated in Fig. 2 where athermostat 30 disposed .in the vapour zone controls the supply ofheating medium to the coils 16 by means of a valve 31.

Alternative or as a supplement to the automatic regulation by thethermostats, a series of refrigerating coils 26 may be provided at theopen entry 13 and exit 14 of the trough 12 to prevent leakage of thevapour by causing condensation on the vapour attaining their vicinity sothat the condensed vapour falls to the base 17 of the bath, while ifdesired the refrigerating pipes 26 may be pivotally and adjustablymounted so as to vary the opening to atmosphere at the entry 13 and theexit 14 according to particular requirements. 7

After treatment in the vapour bath 6 the conveyor 1 carries the articlesin the pickling bath'8 being directed by guide pulleys 9 suitablyattached to the bed 5 of the apparatus.

The pickling bath 8 in its simplest form comprises an open rectangularwell 27 containing acid or other pickling solution usually sulphuric,hydrochloric or phosphoric acid depending on the particular articlesunder treatment, and the finish which it is desired to apply to them, sothat the articles 18 passing along-the conveyor are simply dipped in theliquid of the pickling bath so as to remove any scale, although ifrequired, provision may be made for more prolonged contact between thearticles and the liquid of the bath.

To enable the pickling bath 8 to be emptied when required a drain 32 isprovided and is closed by a suitable tap 33.

In order to remove any acid which the surfaces of the articles 18 undertreatment may retain after passage of the articles through the picklingbath 8, which would deleteriously affect the finished article, theconveyor 1 next directs the articles 18 by means of the guide pulleys 11into a water wash 10 shown identical in construction with the picklingbath 8, but containing plain water, the art cles 18 moving along theconveyor being dipped in this water so that any traces of acid areremoved before discharge of the articles at 29.

Any other suitable wash can be employed if desired, while provision maybe made for drying the articles 18 by means of hot air zones or thelike.

It will be seen from Figs. 2, 3 and 4 that the conveyor 1 is of duplexnature with double carriers 2 and 3, and that transverse members 34connect the two chains of the conveyor and serve for the attachment ofthe articles 18 to be cleaned. In the example shown each transversemember 34 is arranged to carry a pair of articles 18 and the series oftransverse members are arranged equidistantly around the conveyor sothat an menses equal distance se arates the articles carried. It will beun erstood that although trichlorethylene forms a conve ient vapour solvent for use in the vapour bath, any other suitable solvent may beutilized depending onthe purpose in view, and that the pickling bathsand water washes may also be constituted by any suitable solutiondepending on the particular conditions required for the articles undertreatment.

It will also be understood that no claim is herein made to the vapourtreatment of the articles per se or to the apparatus for carrying outthis treatment, such treatment and apparatus being the subject ofco-pending application Serial No. 302,038 filed the 25th August, 1928.

lVhat we claim is:

1. In a combination of apparatus of the character described, a pluralityof baths, means for supplying a solvent in vaporous form and at adesired temperature to one of the baths, a pickling solution in anotherof the baths, means for controlling the temperature of the vapor in saidfirst bath, means for immersing an object to he degreased within thevapor whereby some of the vapor will be condensed upon the relativelycooler object, and the temperature of the object raised, means forremoving the ob'ect from said bath, the temperature of the object andthe volatile character of the solution causing degreased material on thesurface of the object to assume a dry condition, and means for immersingthe ob ect within the pickling bat-h, wherein the dry residue will beremoved.

2. In a combination of apparatus of the character described, a conveyorsystem for immersing articles to be degreased progressively within aplurality of supplying vapor to one of said baths, a pickling solutionin another of said baths, means for maintaining the va or in the firstbath at a temperature consi erably higher than the temperature ofarticles to be immersed therein for degreasing, whereby some of saidvapor will condense upon the articles and raise the temperature of thearticles, the vapor being relatively volatile solvent, so that thearticles at their higher temperature will cause the evaporation ofcondensate upon the removal of the articles from the bath, the articlesbeing delivered by the con- 55 veyor in substantially-dry condition tothe pickling bath for removal of dry residue.

3. A combination of apparatus for converting greasy material to dryresidue and then removing the residue, comprising a 60 vapor bath and aliquid pickling bath, means for converting liquid solvent into a vaporand feeding said vapor at a desired temperature to the vapor bath, meansfor immersing an object having a surface bearing 65 reasy materialwithin the vapor bath, said means being adapted to remove the objecttherefrom and then immerse it within the pickling bath, said surfacebeing adapted to become substantially dry during the interval betweenits removal from the vapor bath and its immersion within the picklingbath.

In testimony whereof we afiix our signatures.

. ALEXANDER FOWLER.

KENNETH JAMES RENNIE ROBERTSON.

aths, means for

